Wheel bearing devices have developed from a structure referred to as a first generation that a double-row roller bearing singly, to a second generation in which a vehicle body attaching flange is integrated with an outer member, to a third generation in which an inner rolling contact surface is integrally formed on one roller bearing of a double-row roller bearing on an outer periphery of a hub wheel to which a wheel attaching flange is integrated, to a fourth generation in which a constant velocity universal joint is integrated with a hub wheel, and an inner rolling contact surface of the other roller bearing of the double-row roller bearing is integrally formed on an outer periphery of an outer joint component configuring the constant velocity universal joint.
For example, in Patent Document 1, a wheel bearing device referred to as the third generation is described. As shown in FIG. 13, the wheel bearing device referred to as the third generation includes a hub wheel 102, a constant velocity universal joint 104, and an outer member 105. The hub wheel 102 includes a flange 101 that extends in an outer diameter direction. An outer joint component 103 of the constant velocity universal joint 104 is fixed onto the hub wheel 102. The outer member 105 is disposed on an outer circumferential side of the hub wheel 102.
The constant velocity universal joint 104 includes the outer joint component 103, an inner joint component 108, a plurality of balls 109, and a cage 110. The inner joint component is disposed within a bowl-shaped section 107 of the outer joint component 103. The ball 109 is disposed between the inner joint component 108 and the outer joint component 103. The cage 110 holds the ball 109. A spline section 111 is formed on an inner circumferential surface of a center hole of the inner joint component 108. A spline section on an end section of a shaft (not shown) is inserted into the center hole. As a result, the spline section 111 on the inner joint component 108 side and the spline section on the shaft side are engaged.
The hub wheel 102 includes a cylinder section 113 and the flange 101. A short cylindrical pilot section 115 is provided such as to project from an outer end face 114 (an end face on a counter joint side) of the flange 101. A wheel and a brake rotor (not shown) are mounted on the pilot section 115. The pilot section 115 includes a large-diameter first section 115a and a small-diameter second section 115b. The brake rotor is fitted onto the first section 115a The wheel is fitted onto the second section 115b. 
A small-diameter stepped section 116 is provided on an outer circumferential surface of an end section of the cylinder section 113 on the bowl-shaped section 107 side. An inner ring 117 is fitted onto the small-diameter stepped section 116. A first inner raceway surface 118 is provided near a flange on the outer circumferential side of the cylinder section 113 of the hub wheel 102. A second inner raceway surface 119 is provided on an outer circumferential surface of the inner ring 117. A bolt attaching hole 112 is provided in the flange 101 of the hub wheel 102. A hub bolt for fixing the wheel and the brake roller onto the flange 101 is attached to the bolt attaching hole 112.
Double rows of outer raceway surfaces 120 and 121 are provided on the inner periphery of the outer member 105. A flange (vehicle body attaching flange) 132 is provided on the outer periphery of the outer member 105. The first outer raceway surface 120 of the outer member 105 and the first inner raceway surface 118 of the hub wheel 102 face each other. The second raceway surface 121 of the outer member 105 and the raceway surface 119 of the inner ring 117 face each other. A rolling element 122 is interposed therebetween.
A stem shaft 123 of the outer joint component 103 is inserted into the cylinder section 113 of the hub wheel 102. A screw section 124 is provided on an end section of the stem shaft 123 at a section counter to the bowl-shaped section. A spline section 125 is formed between the screw section 124 and the bowl-shaped section 107. A spline section 126 is formed on the inner circumferential surface (inner diameter surface) of the cylinder section 113 of the hub wheel 102. When the stem shaft 123 is inserted into the cylinder section 113 of the hub wheel 102, the spline section 125 on the stem shaft 123 side and the spline section 126 on the hub wheel 102 side are engaged.
Then, a nut component 127 is screwed onto the screw section 124 of the stem shaft 123 projecting from the cylinder section 113, thereby connecting the hub wheel 102 and the outer joint component 103. At this time, an inner end face (back surface) 128 of the nut component 127 and an outer end face 129 of the cylinder section 113 come into contact. In addition, an end face 130 of the bowl-shaped section 107 on the stem shaft side and an outer end face 131 of the inner ring 117 come into contact. In other words, as a result of the nut component 127 being tightened, the hub wheel 102 is held sandwiched between the nut component 127 and the bowl-shaped section 107 via the inner ring 117. As a result, the outer joint component 103 and the hub wheel 102 are positioned in an axial direction, and a predetermined preload is applied to the wheel bearing device.
Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-340311